Miniature electrical relays have found wide and varied applications in the Telecommunications and Electronic Industry. Although solid state devices have recently replaced relays in many telecommunication and electronic systems, relays still offer many advantages in terms of cost and reliability in electrical circuit applications.
Relay constructions may comprise a base member molded of insulating material having terminal members embedded therein which extend below the relay base member and are formed to be inserted into holes drilled into a mounting surface, for example a circuit board, to mount the relay on the mounting surface. A bobbin member having a coil winding connected with ones of the terminal members embedded in the relay base member is generally positioned on the base member with the coil winding enclosing a contact assembly. The contact assembly has contact structures such as pole-piece members located at one end of an envelope member and a stem member located at the opposite end of the envelope member so as to engage the pole-piece members. The contact assembly pole-piece and stem members are wired to others of the terminal members embedded in the relay base member so that an electrical voltage applied to the relay terminal members connected to the bobbin coil winding generates a magnetic field to enable the contact assembly stem member to engage and disengage the pole-piece members and selectively establish electrical paths between ones of the other terminal members.
One problem arises with these relays in that holes must be drilled in the mounting surface. Another problem is that machines for installing the relays into the holes of the mounting surfaces must be designed so as to precisely align the relay terminal members with the mounting surface holes such that the relay may be installed on the mounting surface by inserting the relay terminal members into the holes without damaging either the terminal members of circuitry of the mounting surface. Yet another problem arises with these types of relays in that the terminal members are embedded in the relay base member thereby requiring molding machinery that precisely holds the terminal members during the process of molding the relay base member.
Accordingly, a need exists for an electrical relay having terminal members for mounting the relay on the surface of a circuit board without pre-drilling holes in the circuit board. A need also exists for a relay wherein terminal members for mounting the relay on a mounting surface may be installed on the relay without molding the terminal members in the relay base member.